Pressure Relief HD 3530-20X10 Specialty Products For evaporative coolers or central

For evaporative coolers or central blower systems

with color matching Phillips posi-drive screws * All component parts

Standard Features 1” rim size (2” larger than nominal duct size / order size) 14 gauge steel construction Countersunk mounting holes for a flush appearance 1-27/32” Wide x 11/32” High slots on staggered centers

Eighteen air patterns

Pressure Relief HD 3530-20X10 Specialty Products For evaporative coolers or centralh3. Standard Features * 3510 Vertical mount * 3520 Horizontal mount air up * 3530 Horizontal mount air down * Designed to open with negative or positive pressures for intake or exhaust air * Felt edge blades to hold noise to a minimum * Aluminum construction * Blade to blade linkage * 1 4" pivot pins in nylon busings * Maximum size 24 x 24 * Mill finish h3. Options * Sleeve variations * Mounting flange * Adjustable counter balance to adjust various